One of the greatly annoying things about the Necron codex is the lack of useful "freestanding" 5 point upgrades. I mean in most codices if you end up 5 points short, you can just toss a melta bomb on a likely model and be done with it. Sure, there are 5 point upgrades, but you you have to take them for the entire unit or they are direct weapon replacements for character models. So, it takes a little juggling to straighten things out.
1x Overlord w/ WS, MSS, Orb, SPW on foot with Warriors
1x Immortalsx9 (Gauss) w/ Cryptek of Destruction (Solar Pulse) & Lord (WS, MSS, Orb)
1x Immortalsx9 (Tesla) w/ Cryptek of Destruction (Solar Pulse) & Lord (WS, MSS, Orb)
1x NWx18 w/ 2x Crypteks (2xVoltaic staff, 2x Electric field)
1x NWx5 w/ Cryptek (Tremorstave) in a Ghost Ark (GA)
1x Spyders w/ Gloom Prism
2x Annihilation Barge
2x Night Scythes (DT for Immortals, but usually empty.
Changes in bold: -1 Immortal from each squad, -2 Warriors from the big squad which frees up 60 points, so now I'm short 55. Add in the 10 points to give me the other electric field on the big Warrior squad (if only it could be used offensively...), added a Cryptek with Tremorstave (S4 AP-, 36", Blast) that makes anything hit by it treat all terrain as difficult. Fun and annoying little weapon. If I'd had an extra 5, I would have bought an Eldritch Lance, if I had 5 less, I'd have gone with either a Voltaic Staff or left it with a Staff of Light (AP3 Assault3 is nice in many situations). So, I lost four models and added two back.
I had thought of tossing in a little five Warrior foot unit to sit in the back, but that is too easy to kill. If I need a back sitter, I can just pull the little unit out of the Ghost Ark and the Cryptek's 36" weapon will let them do a little dakka, plus give them an Everliving model so it isn't just kill five and go home to eliminate them.